The invention relates to methods and systems for providing quality-of-service on packet-based wireless connections.
The Internet is evolving towards providing QoS (quality-of-service) capabilities, for example to satisfy the requirements of multimedia applications. Applications that demand QoS may signal the request explicitly through signaling protocols such as the Resource Reservation Protocol (RSVP) or through marking of certain fields of the IP header (e.g., the DS field). RSVP is used in Integrated Services (IntServ) to support end-to-end QoS commitment through the reservation of network resources along a data path. To obtain a desired level of QoS, the end applications make service requests using RSVP. These requests dictate the level of resources that have to be reserved across a multitude of networks to provide the desired QoS for the data flow. Each router along the data path has to apply admission control to requests to ensure that they are accepted only when there are sufficient local resources.
There are also draft proposals in IETF (Internet-Engineering Task Force) to support interoperation of RSVP/IntServ and DiffServ to provide end-to-end QoS delivery when a data flow traverses both networks of IntServ and DiffServ. Under the proposal, the edge nodes of DiffServ are capable of performing explicit admission control with respect to RSVP requests and of performing an IntServ-to-DiffServ service (QoS) mapping.
RSVP was originally designed to support QoS in the Integrated Services (IntServ) framework. Currently, only two QoS control services, Guaranteed Service and Controlled-Load Service have been formally specified for use with RSVP. Nevertheless, RSVP itself is separable from the IntServ framework and can be used as a general-purpose QoS signaling protocol for a variety of QoS control services with various setup mechanisms. All existing RSVP uses have been for wire line applications. The objects defined in RSVP can carry different information to meet different application and QoS control service requirements.
As wireless networks, and in particularly CDMA networks, evolve to support IP capabilities, they need an effective mechanism for QoS signaling over-the-air. It would be advantageous if CDMA networks could support the end-to-end QoS signaling adopted by the wire line IP networks.
In wire line applications, IP layer signaling plays a key role in configuring successful end-to-end QoS delivery. The existing cdma2000 signaling only allows the establishment of a service configuration between the mobile terminal and the radio access network. There is no support for end-to-end signaling for explicit QoS negotiation required by applications from both ends. There is a need for a mechanism to interpret and process IP layer (or other layer 3) signaling messages in a cdma2000 context.
It is an object of the invention to obviate or mitigate one or more of the above-identified disadvantages.
Various aspects of the invention provides a method, a base station and a wireless station, all adapted to allow a wire line QoS signaling schema to be applied to wireless applications, thereby facilitating an end-to-end QoS solution for connections including wireless links or at least facilitating a QoS solution from the wireless terminal to wherever the QoS solution might end within the wireline network.
In one aspect, the wire line QoS signaling schema employed is RSVP. In this aspect, the invention provides a method of extending RSVP QoS signaling to a wireless network by intercepting a PATH message to/from a mobile terminal served by the wireless network, modifying its contents to reflect constraints of the wireless network and forwarding the PATH message; intercepting a RESV message received in response to the PATH message; after intercepting the RESV message, in sequence: performing a QoS mapping from a RSVP QoS specified in the RESV message to wireless network parameters, checking if an existing wireless traffic channel satisfies the wireless network parameters and if not coordinating the establishment of a wireless traffic channel which satisfies the wireless network parameters, and forwarding the RESV message.
Thus, the RSVP messages themselves are used to perform the signaling or the wireless connection, but their parameters are changed to reflect constraints introduced by the wireless connection. Furthermore, preferably, only after the wireless connection is actually established is the RESV message forwarded. This solution can be applied to both mobile-originated and mobile terminated RSVP requests.
When a traffic channel is in existence, the RSVP messages can be sent over the existing traffic channel. After the QoS mapping has been performed, if the existing traffic channel cannot satisfy the resulting wireless parameters, a new service negotiation takes place to establish a traffic channel which has the required parameters.
When a traffic channel has not been yet established, some messages such as the PATH message may be sent with a short data burst service if one is available thereby eliminating the need to perform two traffic channel setups for the case where the initially setup traffic channel would not meet the QoS, instead only requiring a single traffic channel setup to be performed to setup a traffic channel with the required characteristics.
The above described embodiments have focussed on RSVP applications. More generally, the invention can be applied to any wire line QoS signaling schema. An embodiment provides a method of extending a wire line QoS signaling schema featuring QoS messages to a wireless network consisting of intercepting all QoS messages addressed to or received from a mobile terminal served by the wireless network, at least one of the QoS messages specifying a wire line QoS in accordance with the wire line QoS signaling schema, modifying contents of the QoS messages to reflect constraints of the wireless network, forwarding the QoS messages thus modified subject to the constraint that any message confirming the establishment of a connection between the mobile terminal and the wireless network is not forwarded until after performing a QoS mapping from a wire line QoS specified in the messages to wireless network parameters, checking if an existing wireless traffic channel satisfies the wireless network parameters and if not coordinating the establishment of a wireless traffic channel which satisfies the wireless network parameters.
Another broad aspect of the invention provides a radio network component or combination of components adapted to provide the required QoS mechanism. This might for example be implemented in a base station. The component(s) are adapted to include an RSVP daemon for intercepting RSVP messages, a QoS signaling adaptation module for mapping RSVP QoS to wireless parameters, for modifying RSVP messages to reflect wireless constraints, and for releasing RSVP messages to be forwarded after they have been modified subject to the constraint that any message confirming a connection to a mobile terminal having a particular RSVP QoS is not sent until a wireless connection having wireless parameters sufficient to at least meet the RSVP QoS has been established or verified to exist, and a QoS signaling adaptation control module for requesting a wireless connection based on the wireless parameters.
Other embodiments feature the use of layer 3 cdma2000 messages to encapsulate RSVP messages.